Extended spectrum--lactamase producing Escherichia coli and Klebsiella pneumoniae causing urinary tract infection

Extended spectrum β-lactamase (ESBL) producing Escherichia coli and Klebsiella pneumoniae causing urinary tract infection (UTI) constitutes a significant therapeutic challenge.  The aim of this study was to investigate the frequency of ESBL producing Escherichia coli and Klebsiella pneumoniae isolated from urine samples. Clinical isolates of multidrug resistant Gram negative rods (n=102) were taken from urine specimens from tertiary care hospital Lahore. Micro-organisms were identified on the basis of their morphology, cultural characteristics, and confirmed using API 20E. Identified E. coli and K. pneumoniae were subjected to susceptibility testing using Kirby-Bauer disc diffusion method as per CLSI guidelines. Furthermore, phenotypic confirmation of ESBL production was done according to CLSI guidelines. Out of 102 multidrug resistant Gram negative rods 97 (95%) were ESBL producers isolated from different urine specimens from different wards of hospitals (emergency, ICU, urology ward); among these 64 (66%) were E. coli and 33 (34%) were K. pneumoniae.  Antimicrobial susceptibility pattern of ESBL producing pathogens showed that 75% of these pathogens were resistant to ciprofloxacin whereas most effective drug was meropenem and pipracillin+tazobactam.  Meropenem could be used as an alternative treatment option for UTI related to ESBL producing E. coli and K. pneumoniae. High prevalence of these ESBL producing pathogens are alarming and need special consideration.   Key words: Extended spectrum β-lactamases, urinary tract infection, Escherichia coli, Klebsiella pneumoniae.